Angel Investors Get Backers of Their Own

Silicon Valley venture capitalists often invest in the youngest start-ups. But now some venture-capital firms are partly outsourcing that investing to others.

Venture-capital firms such as Norwest Venture Partners and Sutter Hill Ventures have been putting some of their money into funds run by "super angel" investors. Super angels, a growing class in Silicon Valley who invest their own dollars but also have raised money...